Thulium fiber laser in urology: physics made simple

Abstract

Purpose of reviewIn this narrative review, we will focus on a novel thulium fiber laser's physical properties in terms of its clinical applicability.Recent findings TFL has successfully moved forward from the preclinical trials into clinical practice and now is being widely used in clinics around the world. The available data suggest that the device effectively operates in soft tissues -benign prostate hyperplasia (BPH) and bladder tumors, as well as in lithotripsy. Also, the first promising results were obtained from laparoscopic surgery showing its possible applicability in the management of renal cell carcinoma. The constructional changes in fiber laser's design, lead to alteration of laser-tissue interactions, which resulted in clinical advantages of the device. Yet, the exact mechanism often is considered complex for understanding. With this work, we are aiming to build a bridge between biophysics and clinical practice and give a simple explanation of how the devices is working and why the knowledge of it is important for a clinician.

Thulium fiber laser in BPH surgery: Bench to bedside - a systematic review on behalf of YAU Urotechnology Working Group

“…As for QCW TFL, it has established itself as a effective and safe device for EEP which is not inferior in these terms to Tm : YAG and Ho : YAG. QCW TFL may be safer than Tm : YAG in terms of carbonizationthe quasi-continuous mode decreases the thermal damage to tissue reducing carbonization and simplifying the intraoperative navigation (16,17). Unfortunately, there is no one preclinical comparison of those lasers yet.…”

“…TFL construction substantially differs from Tm : YAG. Firstly, the YAG laser medium was replaced with thulium doped silica fiber (16,17). Thulium was chosen because the wavelength it creates is the closest to the water absorption peak (TFL -1940 nm, water -1910).…”

Thulium Fiber Laser: Bringing Lasers to a Whole New Level

“…A recent randomized trial of HoLEP and TFL laser enucleation of the prostate (ThuFLEP) revealed that the deeper ablation and coagulation zones with TFL do not translate into higher rates of urinary incontinence and irritation after surgery (assessed with QUID, ICIQ-MLUTS) [17] . Despite a comparable bleeding rate in these trials, TFL, owing to its better coagulation ability, should still be promising in terms of lower bleeding rates and faster hemostasis, which was confirmed in ex vivo tests [11] .…”

“…TFL is different in that the medium is made from woven silica fiber that is chemically doped with thulium ions. This construction means that TFL devices are much smaller then Ho:YAG and Tm:YAG and prevents extensive heating; an air cooling system is sufficient for TFL, in contrast to the water cooling systems required for Ho:YAG and Tm:YAG [11] . However, this is not the only advantage: solid-state lasers use flash lamps as the energy source for the firing, while TFL uses small diodes.…”

“…As mentioned previously, TFL does not use flash lamps or water cooling, relying instead on a diode laser as source and air cooling. Thus, as a high-power machine, TFL uses a standard power outlet and has significantly lower noise in comparison to Ho:YAG [11] . Moreover, this may also increase the cost effectiveness of the device, as the diode laser used as a source has a longer lifespan than a flash lamp and the air-cooling system does not require coolant replacement [19] .…”